1988 XJ Tranny

So I have noticed that out of the blue, it seems like maybe my tranny is slipping. I say maybe because it does it mostly after coming to a stop or slowing way down. When you accelerate again the rpm's climb but you do not accelerate. Kind of like when a clutch is going out, only this is an auto. It doesn't do it all the time, and just did it randomly out of nowhere one night on the way home from work. I don't know if it matters, but the tranny/t-case combo I have, does have the option for full time and part time 4x4. I'm curious if since it was so random( and has had no prior issues) if a simple flush of the tranny and maybe a new filter could fix it? I have a parts rig with a tranny in it, but would like to avoid pulling the tranny for no reason. Also should mention that when it does finally start to move again, it clunks, fairly hard depending on how much gas you give it. When you are stopped completely and try taking off, if almost feels like your trying to break stand it. Any help would be awesome,

Thanks guys

Tyler:cheers:

i would at least check and change the fluid and filter if necessary. couldnt hurt.